The present invention relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides an expandable float shoe and associated methods.
In a well in which intersecting wellbores are utilized, it is known to convey a wellbore junction into the well and position it at the desired wellbore intersection. In one method, the wellbore junction is conveyed into the well in a compressed shape, so that the wellbore junction may be displaced through casing above the wellbore intersection. The wellbore junction is then expanded at the wellbore intersection. This expansion provides enhanced access and flow through the junction.
Expansion of the wellbore junction may be accomplished by applying pressure internally to the junction, thereby inflating the junction. For example, one leg of the junction may be compressed and placed against the remainder of the junction, and then pressure applied internally to the leg causes it to move and expand outward. Unfortunately, such wellbore junction designs have met with limited success in satisfactorily expanding the junction leg.
In addition, a rigid closure is used to contain the pressure applied to the junction leg. This rigid closure increases the difficulty experienced in compressing the wellbore junction. Furthermore, the rigid closure is difficult to cut through when it is desired to provide access and flow through the leg after it is expanded.
From the foregoing, it can be seen that it would be quite desirable to provide an improved apparatus and method for expanding structures in a well.
In carrying out the principles of the present invention, in accordance with an embodiment thereof, an expandable float shoe is provided which may be attached to a leg of a wellbore junction for use in expanding the junction. The float shoe utilizes a body and closure which are compressed with the junction leg, and which are designed to enhance the expansion operation and subsequent cutting through the float shoe to provide access and flow through the junction leg. Associated methods are also provided.
In one aspect of the invention, an expandable float shoe apparatus is provided. The apparatus includes a generally tubular body having first and second opposite ends, and a closure preventing flow through the body first end. The body and closure are formed into a compressed shape.
A force transmitting material may be contained within the float shoe body. The material may be disposed between the closure and a membrane. The membrane is exposed to the pressure applied to the wellbore junction, but prevents this pressure from being transmitted to the closure. The material transmits a force (produced by the pressure applied to the membrane) to the interior of the body, thereby causing the body to expand.
In another aspect of the invention, an expanding wellbore junction system is provided. The system includes a wellbore junction having at least one compressed leg, so that the wellbore junction is conveyable through a tubular string in a well, a generally tubular body attached to the leg, and a closure preventing flow through the body. Both the body and the closure are compressed. Pressure applied to an interior of the wellbore junction expands the leg, body and closure outward in the well.
In yet another aspect of the invention, a method of expanding a wellbore junction in a well is provided. The method includes the steps of attaching an expandable float shoe to a leg of the wellbore junction, compressing the float shoe and the leg, positioning the wellbore junction in the well, and expanding the float shoe and the leg in the well.
These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings.